/ Check-in [45301442]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Modify documentation to explain default value of "pragma synchronous". No code changes. (CVS 2459)
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1:453014421e9a739b47d4c28b0342454e4c686199
User & Date: danielk1977 2005-05-16 02:13:18
Context
2005-05-16
22:37
Fix an uninitialized variable. Ticket #1244. (CVS 2460) check-in: 582cb77d user: drh tags: trunk
02:13
Modify documentation to explain default value of "pragma synchronous". No code changes. (CVS 2459) check-in: 45301442 user: danielk1977 tags: trunk
2005-05-11
14:28
Change to the lemon parser suggested by Geert Janssen. Appears to have no impact on SQLite. (CVS 2458) check-in: 6fda6008 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to www/pragma.tcl.

1
2
3
4
5
6
7
8
9
10
11
...
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256




257
258
259
260
261
262
263
264
#
# Run this Tcl script to generate the pragma.html file.
#
set rcsid {$Id: pragma.tcl,v 1.13 2005/03/31 21:02:46 drh Exp $}
source common.tcl
header {Pragma statements supported by SQLite}

proc Section {name {label {}}} {
  puts "\n<hr />"
  if {$label!=""} {
    puts "<a name=\"$label\"></a>"
................................................................................
    The first (query) form will return the setting as an 
    integer.  When synchronous is FULL (2), the SQLite database engine will
    pause at critical moments to make sure that data has actually been 
    written to the disk surface before continuing.  This ensures that if
    the operating system crashes or if there is a power failure, the database
    will be uncorrupted after rebooting.  FULL synchronous is very 
    safe, but it is also slow.  
    When synchronous is NORMAL (1, the default), the SQLite database
    engine will still pause at the most critical moments, but less often
    than in FULL mode.  There is a very small (though non-zero) chance that
    a power failure at just the wrong time could corrupt the database in
    NORMAL mode.  But in practice, you are more likely to suffer
    a catastrophic disk failure or some other unrecoverable hardware
    fault.  So NORMAL is the default mode.
    With synchronous OFF (0), SQLite continues without pausing
    as soon as it has handed data off to the operating system.
    If the application running SQLite crashes, the data will be safe, but
    the database might become corrupted if the operating system
    crashes or the computer loses power before that data has been written
    to the disk surface.  On the other hand, some
    operations are as much as 50 or more times faster with synchronous OFF.




    </p></li>


<a name="pragma_temp_store"></a>
<li><p><b>PRAGMA temp_store;
       <br>PRAGMA temp_store = DEFAULT;</b> (0)<b>
       <br>PRAGMA temp_store = FILE;</b> (1)<b>
       <br>PRAGMA temp_store = MEMORY;</b> (2)</p>



|







 







|





|







>
>
>
>
|







1
2
3
4
5
6
7
8
9
10
11
...
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
#
# Run this Tcl script to generate the pragma.html file.
#
set rcsid {$Id: pragma.tcl,v 1.14 2005/05/16 02:13:18 danielk1977 Exp $}
source common.tcl
header {Pragma statements supported by SQLite}

proc Section {name {label {}}} {
  puts "\n<hr />"
  if {$label!=""} {
    puts "<a name=\"$label\"></a>"
................................................................................
    The first (query) form will return the setting as an 
    integer.  When synchronous is FULL (2), the SQLite database engine will
    pause at critical moments to make sure that data has actually been 
    written to the disk surface before continuing.  This ensures that if
    the operating system crashes or if there is a power failure, the database
    will be uncorrupted after rebooting.  FULL synchronous is very 
    safe, but it is also slow.  
    When synchronous is NORMAL, the SQLite database
    engine will still pause at the most critical moments, but less often
    than in FULL mode.  There is a very small (though non-zero) chance that
    a power failure at just the wrong time could corrupt the database in
    NORMAL mode.  But in practice, you are more likely to suffer
    a catastrophic disk failure or some other unrecoverable hardware
    fault.
    With synchronous OFF (0), SQLite continues without pausing
    as soon as it has handed data off to the operating system.
    If the application running SQLite crashes, the data will be safe, but
    the database might become corrupted if the operating system
    crashes or the computer loses power before that data has been written
    to the disk surface.  On the other hand, some
    operations are as much as 50 or more times faster with synchronous OFF.
    </p>
    <p>In SQLite version 2, the default value is NORMAL. For version 3, the
    default was changed to FULL.
    </p>
</li>


<a name="pragma_temp_store"></a>
<li><p><b>PRAGMA temp_store;
       <br>PRAGMA temp_store = DEFAULT;</b> (0)<b>
       <br>PRAGMA temp_store = FILE;</b> (1)<b>
       <br>PRAGMA temp_store = MEMORY;</b> (2)</p>